Should you find error messages in /etc/httpd/logs/error_log such as

[Tue Mar 28 04:29:42 2006] [notice] child pid 24546 exit signal File size limit exceeded (25)

This means that you have a log file that is great than 2GB in size. To fix this run

cd /etc/httpd/domlogs
du -sh * | grep [0-9]G

This should show you the file that is causing issues e.g. domain.com.log. To reset it, but loosing the webstats run

cd /etc/httpd/domlogs
rm domain.com.log
touch domain.com.log
/etc/init.d/httpd stop
/etc/init.d/httpd start

Do not use just an Apache restart but a full stop/start to make sure it closes all its old files

To change the SSH port number login as root, and edit /etc/ssh/sshd_config

Find the line that says Port 22 and change 22 to any number between 1024->65535 (above 30000 is best) and save the file.

Once done, run:

/etc/init.d/sshd restart

Now start a new SSH session (don’t close your existing one), to make sure that you can get in.

To upgrade Apache on cPanel login via SSH and then run

/scripts/easyapache

Option 7

Scroll down to Php Module

Make sure either Version 4.4.x is selected (using the space bar) or Version 5.1.4

Press TAB to select Exit and then Enter to exit

Once at the main menu press TAB to select EXIT and press Enter

Say “Yes” to “Do you want to save this apache configuration?”

Apache will now recompile and may take 30-40 minutes depending on the server

If you receive the following message, then you have an invalid cPanel license:

Content-type: text/plain

X-DES-KEY: generate error
Invalid Lisc File

When you log into cPanel WHM, you need to do one of two things:

Check your main server IP at http://verify.cpanel.net to verify that your license is valid. If it is, issue the command /usr/local/cpanel/cpkeyclt which will reset the license file on the server. This should fix your problem.

To check the memory usage on Virtuozzo, you can either login to the VZPP and check the privvmpages in the QoS Alerts or login via SSH and copy/paste the following command:
awk ‘/privvmpages/ {print “Used “$3/256″M out of “$4/256″M burst “}’ /proc/user_beancounters

Which will give output something similar to this:
Used 191.012M out of 1024M burst

If you get presented with the Apache Error 500, then you can check out what is causing the error by looking at the error log; this is located at ‘/etc/httpd/logs/error_log’.

Note: Log locations can vary between distributions.